Hang Gliders, ultralight aircraft, and other pilot weight shifted aircraft, in the late 60's and early 70's, started out flying their craft in the seated position which is a foot forward position. In the early to mid 70's the head first flying position called the prone position became prominent mainly due to the increase of control available flying in the prone position. Unfortunately, as noted by medical journals published in southern California, this switch from a foot first position (seated, supine, and suprone are all feet forward positions) to a head first position (prone) coincided with an increase in serious injuries to pilots.
The suprone position in hang gliding circles is defined as the pilot positioned above the base tube of the A-frame or triangular control frame, flying feet forward, so that the pilot's entire body can move freely in and out of the A-frame of the glider. This has traditionally been done by the pilot placing hands directly on the uprights of the A-frame which has provided a limited range of speed, comfort, and control that can be acquired due to ergonomic considerations.
The traditional suprone pilot flying cannot fully recline and remain within easy reach of the gliders A-frame or control bar. Reclining into the streamlined position places the uprights beyond a pilot's easy reach causing suprone pilots to often resort to remaining hunched forward to grasp the uprights for control, or if fully reclined in the streamlined position, resort to using the aircrafts rear flying wires for weight shift control movements but the rear flying wires of the aircraft were not designed to be used in this manner and do not provide a solid connection with the frame of the aircraft to perform control functions.
All this leaves a suprone pilot flying a hang glider or ultralight with less control over the aircraft compared to other flying positions, such as the prone position, which is the head first position.
Less control, limited speed range, and lack of comfort are the primary reasons suprone flight has never gained in popularity even though the suprone pilots body positioned feet first within the safety of the A-frame with the base tube of the A-frame directly beneath the pilot's body provides tremendous potential for surviving an impact.
There are three other flying positions historically and currently used to pilot a weight shifted aircraft. I will list them in order of current popularity. The positions are prone, supine and seated in addition to the suprone position described earlier, with suprone currently the least popular.
In the prone position, a pilot is flying head first like superman, above the base tube which the prone pilot grasps to control the aircraft by shifting his/her weight. The main problem with the prone position is there is nothing to restrict the pilot from swinging forward and upward in the event of a rapid deceleration of the aircraft. This has resulted in numerous upper body injuries and death.
In the supine position the pilot is flying feet first, semi-reclined, with the pilot's legs extended forward and below the base tube. Flying a hang glider in the supine position the pilot's lower extremities are below with the base tube of the A-frame with no crash protection beneath the pilot's body. Another problem with flying in the supine position is it is not convenient to do what pilots call a “hang check” before launching.
A “hang check” is where a helper holds the nose of the glider at the flying angle of attack while the pilot “hangs” in his or her harness to ensure all is well before committing to launch. Those are the two primary problems flying in the supine.
Flying a hang glider in the “seated” position, as commonly defined in hang gliding community, is the pilot remains fairly erect, legs hanging downward and rear of the A-frame, with the base tube of the A-frame in front of the pilot and somewhat level with the pilot's waistline. The main problems with the seated position are the same as in the supine position. No protection for the pilot's lower extremities, limited ability to pull in for speed, inconvenient to perform a “hang check”, and high wind resistance during flight which decreases the aircrafts performance.
Therefore, a need exists for devices which are able to address and solve the safety, control, and comfort issues faced by hang glider and ultralight pilots who seek to pilot their aircraft in the foot forward specifically known as the suprone position which has the potential to be the most comfortable and most survivable position in which to fly such aircraft. A further need exists for novel devices which enable a suprone pilot to fully recline and remain within easy reach of the A-frame or control bar of an ultra light aircraft.